Waterproofing with granular asphalts

ABSTRACT

Granular, powdery and flaky asphalts are applied to a base material on the work site and then melted to form a waterproof layer and resultant asphalt roofing material.

United States Patent 1 1 1 11 3,762,975

Iwasaki et a1. Oct. 2, 1973 WATERPROOFING WITH GRANULAR [58] Field of Search 117/21, 32; 156/71, ASPHALTS 156/283; 161/236; 404/77; 61/36 R [75] Inventors: Hajime Iwasaki; Yasuo Tomita, both of Tokyo; Takashi Takase, [56] References Cited Narashino; Hirokasu Saitoh, Omiya, UNITED STATES PATENTS all of Japan 1,925,282 9/1933 Robinson 117/21 2,210,348 3 1940 SWOp..... [73] Assignee: MItsuboShI-Sangyo Co., Ltd., Tokyo, 3,227,637 M966 Deflanm Japan 2,774,383 12/1956 Kidd 117/21 X '1 d: 1 197 [22] e y 19 1 Primary ExaminerEdward G. Whitby [21] Appl. No.: 164,126 Att0rney--E. F. Wenderoth et a1.

[30] Foreign Application Priority Data [57] l fz lf h l l Granu ar, powdery an a y asp a ts are app ied to a 4 July 1970 Japan 5/62254 base material on the work site and then melted to form 52 US. Cl. 156/71, 117/21, 117/32, layer and resultant asphalt mate 156/283, 161/236, 404/77 ['51] Int. Cl. E04b H64 6 Claims, N0 Drawings WATERPROOFING WITH GRANULAR ASPHALTS This invention relates to an effective waterproofing method, which utilizes the quick-melting property of granular, powdery and flaky asphalt materials.

In the conventional asphalt heat-working process, lumpy asphalt is melted and spread over the ground to be waterproofed. Asphalt roofings are then pasted and piled several times to form a waterproof layer. As there is a danger of accident or fire during melting, the positioning of the required kiln is limited. There are problems of thermal control and transportation of melted materials. Heat deterioration of the melted aspahlt stored in the kiln cannot be-avoided or neglected in practice. Used asphalt roofings, which are wrinkled by moisture absorption or drying during storage, tend to snake during the pasting. When the asphalt roofing is pasted with melted asphalt, it suddenly foams to make bubbles in the layer, reduce the strength and elongation, and damage its adhesive property and durability. When the base material is an organic fiber, it is attacked by corrosion. Although asphalts can be bonded together by means of melted asphalt at approximately 200C, when an antitack mineral dust is spread and pasted on the asphalt roofing, bonding is checked. In order to achieve efficient work, meanwhile, it is necessary to insure a continuous supply of melted asphalt. At present, therefore, asphalt is heated to a greater extent than required. As the fluidity is subsequently increased, thickness cannot be obtained. In obtaining the asphalt roofing paste layer of the required even thickness, accordingly, pretreatment application, and the pasting over several layers are required, and the work load is increased. In addition, troublesome work and extra skill are required for working the joints and convexes of the asphalt roofing.

As the waterproof layer exposed to the atmosphere is subject to ultraviolet rays, radiant heat, ozone, oxygen, water, poison gas, etc., its resistance against them must be adequate. Waterproof layers would be damaged by cracks originating from the ground concrete, etc. In case the waterproof layer is limited to the cinder concrete layer, more problems come into question.

When the adhesion becomes imperfect due to the presence of air, moisture and water entrapped among the waterproof layers, there is a danger of the waterproof layers breaking one another due to the steam pressure subsequent to the thermal increase based upon the solar heat, and the resultant softening of the asphalt.

In case there is a big difference between indoor and outdoor temperature, e.g., during heating the room, warm damp air migrates from the warm room to the cold outdoor through the roof slab, is intercepted by the waterprooflayer and condenses to water due to the temperature drop. The water remains between the waterproof layer and the ground slab, increasing the chance of a rise of the waterproof layer.

In case various insulating materials of synthetic resin are inserted between the waterproof layers and the slabs to prevent the heat loss and the moisture condensation on the ceiling surface, they must be pasted down with melted asphalt, at about 90C. In a conventional method, much labor and troublesome operations are required for such thermal control.

In the conventional method, as mentioned above, even the use of one type of asphalt would be accompanied by various difficulties. The use of several kinds of asphalt to improve the physical property of the waterproof layer and increase durability would, therefore, give rise to more problems. For instance, it is very difficult to adhere asphalt roofings on the (0C) asphalt having large ductility at low temperatures, e.g. 0C, in an attempt to prevent cracking of the waterproof layer, or to form a waterproof layer of high durability by using a specially good weather-proof asphalt for the upper layer.

In some cases, when the heating process cannot be employed because of the construction, shape or other condition of the buildings, structures, etc., a cold pro cess using anasphalt emulsion or solvent-type asphalt is employed for the waterproofing work. In case the asphalt emulsion technique is used, such fibrous material as asbestos, etc., is mixed, or mesh-shaped material is inserted, to increase thickness and strength. As the emulsion generally contains a moisture content of 40-50 percent, volumetric contraction due to the evaporation of water is so large that it is necessary to reduce the application thickness and promote the drying to restore the asphalt as early as possible. In laminating, therefore, several more applications than in the case of the hot process would be required, and evaporation is not necessarily fully conducted in spite of the large loss of time.

With the solvent-type asphalt, also a cold process, asbestos fiber, etc. is mixed, or meshshaped material is inserted, in many cases. As almost half its volume is solvent, the application thickness per unit time is limited in promoting the drying. Because of the large volumetric contraction, it is difficult to obtain a thick dried layer, similar to the case above.

In the U.S. patent application of Yoshio Ushiku and Hirokazu Saitoh, filed June 1, 1971, entitled Crusher for Tenacious Material Such as Asphalt, there is described an apparatus for obtainng such products as granular asphalt (Example 1). Using this apparatus, asphalt granules of various sizes can be obtained. By subjecting these granules to additional mechanical treatment, it is possible to obtain powdery asphalt, and by rolling the powdery asphalt between a pair of rollers, flaky asphalt can be obtained.

The present invention is based on the use of these granular, powdery and flaky asphalt products in preparing waterproof materials for use in, for example, the construction field.

This invention provides a process characterized by spreading the granular, powdery or flaky asphalt material, or mixture thereof, on a ground concrete (ground to be waterproofed); and immediately heating and melting it to form a waterproof layer. When this process is repeated, several waterproof layers can be obtained. As occasion demands, open-mesh, woven or non-woven fabric is applied, the above asphalt materail being spread, heated and melted. Thereafter, the asphalt material is again spread and heated to form a layer, as if an asphalt roofing is being pasted. When this process is further repeated, laminated waterproofing can be obtained.

In the U.S. patent application of Takashi Takase, Tsunekazu I-Iayashi and Hirokazu Saitoh, filed June 9, 1971, entitled Granular Asphalts," thereis a description of using granular, powdery and flaky asphalt materials to make waterproof materials such as asphalt roofing. However, such method is limited to the mass production of asphalt roofing using machines at a manufacturing plant. The present invention is concerned with immediate production of the asphalt roofing on the work site rather than in a manufacturing plant.

When the waterproofing method based upon this invention is employed, defects of the conventional methods can bev avoided. Waterproof layers of quality and composition adaptable to the construction, shape and area of buildings and structures, or for special parts, can be easily formed. Waterproofing work of excellent effects can be easily obtained. According to this invention, the required quantity of granular, powdery or flaky asphalt material is spread over the specified area of the surface-treated ground to be waterproofed and melted, or melted prior to or during spreading by means of an electrical heating roller, etc., which has been adjusted to the proper temperature in accordance with the quality of asphalt material, and the waterproof layers are gradually formed. Unlike the conventional method, melting kilns are useless, while troublesome operations and danger following the transportation of melted materials and the waterproofing work can be done away with. As the materials are melted in a moment to the required temperature, meanwhile, the thermal layer is so small that the heat deterioration of the asphalt material is prevented. Furthermore, as the material has no unnecessary fluidity as found in the conventional method, the desired thickness of the asphalt layer, which required several applications in the conventional method, can be obtained easily in a one-time process.

As the materials used are granular, powdery or flaky asphalt materials, mixtures of materials of the same kind or different kinds can be used.

The granular, powdery or flaky asphalt can be optionally spread over a net, knitted material, woven or non-woven fabric, or a porous-board-shaped synthetic fiber, metallic material or other reinforcing material. Through the holes of the opening section, melted material oozes out to the upper part of the material and permeates among the fibrous materials. Thus a waterproof body is formed as if the asphalt roofing is pasted, when the above treatment is additionally given. As the melting is rapid, heat deterioration of the reinforcing material and asphalt material can also be prevented. As there is no inclusion of such materials as mineral dust on the surface of asphalt roofing, etc., all layers are perfectly melted together without the necessity of a high degree of heat as found in the conventional methods. As a thick incorporated waterproof layer can be easily obtained to prevent initial deterioration, long-term durability can be retained.

When this working method is used, cracks and damage to the waterproof layer can be prevented, to offset cracks caused on the ground concrete, etc., by using an asphalt material of low temperature and high ductility, e.g., granular, powdery or flaky asphalt material of rubber or catalytic reaction asphalt, for the layer adjacent to the ground. If necessary, meanwhile, reinforcing material of high tensile strength and elongation is pasted and incorporated. As the ground crack stress is then dispersed and absorbed, further effects can be achieved. Asphalt roofings provided with a thick layer of soft asphalt of low temperature and large ductility have not so far been used for the reasons of storage, deformation during work, adhesion, etc. When this waterproofing method is used, however, they can be formed easily at the working site. Therefore, the above disadvantage can be removed, and the working effect can be fully displayed.

When the granular, powdery or flaky asphalt mixture, in which such light porous aggregate as perlite, etc., has been mixed in the required ratio, is melted, overlapped and included midway in the waterproof layer or in the lower layer, an insulating layer of required thickness can be easily obtained, heat loss of buildings, etc. reduced, and the invitation to the rise of the waterproof layer prevented. In addition, as the asphalt material of low softening point is used during pasting of existing insulation material of synthetic resin, and the melting can be easily done at the specified temperature, neither deformation nor deterioration results.

When the specified quantity of granular, powdery or flaky asphalt material of required quality is previously slightly heated and melted into the reinforcing material, or when the asphalt materials are so loosely bonded together as to leave a void between them, thereby forming a plastic body possessing flexibility and gas permeability, which is further melted on the working site, efficiency can be increased. When the plastic body is wound, melted and pasted, meanwhile, projections, vertical surfaces, etc., can be easily worked.

When employing the working method as mentioned above, water-prooflayers which have been formed and overlapped are incorporated so that the waterprooflayers from the upper to the lower layer can satisfy its necessary function respectively. In this connection, this method can display a waterproof and durable effect the conventional hot or cold process has never achieved.

When the granular, powdery or flaky asphalt material is applied, a cold working process, thus far not found suitable, becomes possible. Asphalt content of the dripping-type asphalt emulsion cannot theoretically be increased to more than percent. When this method is used, however, it can be increased to more than 70 percent, practically. Asbestos or mineral powder, mixed to increase the consistency of the emulsion and realize hardness, absorbs water, which might adversely affect the dry layers. As the water absorption of the asphalt material is very small, however, the ratio of water con tent in the emulsion is reduced when the asphalt material is mixed. In addition, the residual moisture and the volumetric contraction is reduced, and the moisture is easily evaporated. As compared with the conventional method, therefore, asphalt is more quickly and easily restored, and consequently the thickness of the layer per application is larger. Furthermore, when reinforcing materials or plastic bodies, in which the asphalt material had been pasted to the reinforcing material as mentioned above, are overlapped, thick cold water proof layers of high strength and excellent durability can be easily obtained.

When granular, powdery or flaky asphalt material is mixed into the solvent-type asphalt, which is immediately applied and worked, a layer of good workability, excellent solvent evaporation and small volumetric contraction can be obtained. In obtaining the required thickness, therefore, the number of processes can be reduced favorably. When a plastic body, in which the asphalt material is melted into the above reinforcing material or other reinforcing material, is further pasted, strength and durability can be increased. In case the latter is used, more thickness can be obtained easily,

the process can be shortened, and consequently the term of work can be reduced. According to the work site and condition, the asphalt material can be previously spread, swelled or dissolved by means of a scattered solvent, and immediately dried or further rolled to give the waterproofing work.

In relation to the waterproofing method of this invention, heat and cold processes can be naturally combined with each other in practice. When such minerals as metallic dust, crushed stone, gravel, sand, etc., are spread and pasted on the asphalt layer, or such mineral dust as talc, etc., is mixed into the asphalt material, the weatherproof property and durability can be easily improved. As for the melting method, heating rollers have been mentioned. Melting machines such as a heat panel with a gas fuel burner, etc., can be used, or a hot-air melting process with electric heater or burner can be singly or jointly used.

The following examples are presented by way of illus' tration only, and are not intended to limit the invention described and claimed herein.

EXAMPLE 1 Compound asphalt of softening point 102C, penetration (25C) of 23, and ductility (25C) of 2.5 was granulated into 30 50 mesh size granules, spread over a concrete slab at the rate of 1.6 kglm whose surface had been previously treated with asphalt primer, subse- EXAMPLE 2 Catalytic reaction rubber asphalt of softening point 100C, penetration (25C) 29, and ductility (25C) 9, (C) 3 was granulated into 30 50 mesh size granules, passed between cold rolls and thereby made into a flaky material, spread over a concrete slab at the rate of 1.6 kg/m, whose surface had been treated, and melted at the speed of approximately 4 m per min. by means of an electrical heating roller. A homogeneous, elastic and ductile rubber asphalt layer, approximately 1.5 mm thick was obtained. As a thin asphalt waterproof film, it is useful for lining a water reservoir, channel, etc.

EXAMPLE 3 After proceeding as in Example 1, vinylon mesh roofings were overlapped, the compound asphalt mentioned in Example 1 was spread at the rate of 1.6 kg/m, melted and adhered by an electrical heating roller at the speed of approximately 4 in per min., which had been set at 210C. A homogeneous single waterproof layer (3 m/m) was obtained, which is suitable for use in the simple waterproofing or reinforce pasting work.

EXAMPLE 4 After proceeding as in Example 2, vinylon nonwoven fabrics were overlapped, the flaky rubber asphalt used in Example 2 was spread at the rate of 1.6 kg/m melted and adhered by means of an electrical heating roller, which had been set at C. A homogeneous single waterproof layer of high elasticity, ductility and tensile strength, approximately 3 mm thick was obtained. Ground crack resistance limit of the single waterproof layer, in which the conventional asphalt roofings were adhered by compound asphalt, was less than 1 mm. But the waterproof layer of this method resists a crack 10 mm wide. When it is applied to oscillating high buildings, structures, tunnels, rivetments, etc., it displays efficiency.

EXAMPLE 5 After proceeding as in Example 2, the product of Example 1 was provided with waterproof layers. When coarse sand grains were partly mixed, spread, melted and pasted, it looked like a sandy roofing. It is effective in protecting surfaces. When aluminuium foil pieces were partly spread and adhered, surface finishing work displaying the effect of a thermal reaction was obtained. Because of its insulation effect, it contributes to the protection of the surface.

We claim:

1. A method for waterproofing a ground concrete on the work site which comprises applying at least one of granular, powdery and flaky asplhalt materials to the ground concrete and simultaneously or subsequently melting the asphalt material to form a waterproof layer on the ground concrete, placing a reinforcing material on the waterproof layer, applying at least one of granular, powdery and flaky asphalt materials thereon and simultaneously or subsequently melting the asphalt material into the reinforcing material.

2. The method according to claim 1, wherein a plurality of waterproof layers are consecutively formed.

3. The method according to claim 1, wherein the reinforcing material is a mesh material, a knitted material, a woven fabric, a non-woven fabric, a porous board-shaped synthetic fibrous material or a metallic material.

4. A method for waterproofing a ground concrete on the work site which comprises applying at least one of melted granular, powdery and flaky asphalt materials to the ground concrete to form a waterproof layer on the ground concrete, placing a reinforcing material on the waterproof layer, applying at least one of granular, powdery and flaky asphalt materials to the reinforcing material and simultaneously or subsequently melting the asphalt material into the reinforcing material.

5. The method according to claim 4, wherein the reinforcing material is a mesh material, a knitted material, a woven fabric, a non-woven fabric, a porous board-shaped synthetic fibrous material or a metallic material.

6. The method according to claim 4, wherein a plurality of waterproof layers are consecutively formed. 

2. The method according to claim 1, wherein a plurality of waterproof layers are consecutively formed.
 3. The method according to claim 1, wherein the reinforcing material is a mesh material, a knitted material, a woven fabric, a non-woven fabric, a porous board-shaped synthetic fibrous material or a metallic material.
 4. A method for waterproofing a ground concrete on the work site which comprises applying at least one Of melted granular, powdery and flaky asphalt materials to the ground concrete to form a waterproof layer on the ground concrete, placing a reinforcing material on the waterproof layer, applying at least one of granular, powdery and flaky asphalt materials to the reinforcing material and simultaneously or subsequently melting the asphalt material into the reinforcing material.
 5. The method according to claim 4, wherein the reinforcing material is a mesh material, a knitted material, a woven fabric, a non-woven fabric, a porous board-shaped synthetic fibrous material or a metallic material.
 6. The method according to claim 4, wherein a plurality of waterproof layers are consecutively formed. 